1. Field of the Invention
The invention concerns an oil mist separator for separating off liquid suspended particles from a carrier gas, in particular, a crankcase ventilation gas of an internal combustion engine, including a housing having at least one inlet opening for introduction of the carrier gas and at least one outlet opening for discharge of the filtered carrier gas, wherein arranged in the housing is at least one filter insert through which the carrier gas can flow along a flow direction.
2. Description of Related Art
It is known that in operation of an internal combustion engine so-called blow-by gases are produced, which are to be discharged from a crankcase of the internal combustion engine to avoid an increase in the pressure in the crankcase and to prevent unwanted escape of blow-by gas and oil contained therein. In the closed crankcase ventilation system, that crankcase venting gas or the carrier gas which includes oil and which results from the blow-by gases in the crankcase is recycled to an air inlet of the internal combustion engine, wherein the pressure in the crankcase is usually kept within predetermined component limit values. The carrier gas however contains fine oil droplets and solid particles of an order of magnitude of between about 0.1 μm and 10 μm.
To avoid negative effects of that oil which is contained in the carrier gas on components in the air inlet of the internal combustion engine, it is already known for the oil and the solid particles to be separated off from the carrier gas. For that purpose, inter alia, filter devices are used, which include filter inserts comprising a wire mesh or knitted wire mesh, through which the carrier gas can flow. By virtue of the underlying separation mechanisms and the structure-governed design configuration of such a wire mesh or knitted wire mesh, however, such filter devices achieve only a limited degree of separation when small drop or particle sizes are involved (in particular, in the particle size range of <1 μm). Therefore, it is possible to use, connected downstream of the filter device, a fine filter (for example, a coalescer filter) which can filter out smaller oil droplets than the separating filter.
Oil mist separators are known, for example, from CN 201198776 (Y), JP 2010-248934 (A), and JP 2001-200713 A.